1. Field of the Invention
The present invention relates generally to transmissions and more specifically to a constant torque input infinitely variable automatic transmission, which changes a drive ratio for being driven by a constant torque input.
2. Discussion of the Prior Art
It appears that the prior art does disclose a purely mechanical transmission that automatically shifts a drive ratio to maintain a constant input torque. An automatically shifting transmission is desirable for cyclists, who do not want to be troubled with the need for shifting, yet want to pedal at a constant torque. However, there are other applications besides bicycles, where a constant torque input infinitely variable automatic transmission could be utilized.
U.S. Pat. No. 3,873,128 to Dunder et al. discloses a drive transmission for a bicycle or the like. The Dunder et al. patent includes a housing having a pair of spaced right circular cones oppositely mounted and journaled for rotation within the housing. Means is provided for transmitting rotation of one of the cones to the other. U.S. Pat. No. 3,906,809 to Erickson discloses a transmission having an infinitely variable drive ratio. The Erickson patent includes a variable ratio transmission having a pair of opposed oriented adjacent splined cone shaped members interconnected by a selectively positionable positive gripping drive chain.
Accordingly, there is a clearly felt need in the art for a constant torque input infinitely variable automatic transmission, which changes a drive ratio for being driven by a constant torque input and is purely a mechanical design.